Request for rotation props

[ayepRahman]

Are you making a feature request?

• Is there a plan on making the image rotatable?

[ValentinH]

I've never thought about this but I don't think so. On ricardo.ch, we have a simple button to rotate the image by 90°.

[junbong]

I like this idea.

[ValentinH]

How would you see this feature? What would be the UI?

For mobile, it would be quite intuitive by simply using 2 fingers. However, the biggest question is how to provide a simple interaction on desktop?

[ayepRahman]

Probably pass props of integer in degree 90 etc

On Fri, Jul 12, 2019 at 1:37 PM Valentin Hervieu notifications@github.com wrote:

How would you see this feature? What would be the UI?

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/ricardo-ch/react-easy-crop/issues/47?email_source=notifications&email_token=AGJJD5H5CXPTUR7TXZJL77LP7AKARA5CNFSM4H7L6YM2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODZYXMUI#issuecomment-510752337, or mute the thread https://github.com/notifications/unsubscribe-auth/AGJJD5BW7ONEXRU55Z5QYHDP7AKARANCNFSM4H7L6YMQ .

[ValentinH]

I edited my previous answer.

The API would be quite simple indeed: rotation: number and onRotationChange: number => void.

Any thoughts regarding UI?

[ValentinH]

Actually it could be started with only an external UI for desktop (like a slider), and handle the rotation on mobile within the library.

[ayepRahman]

I like using components from Mui. But anyone can use any JSX element with onClick function to handle the roration. Even slider from Mui which previosuly you shown. Maybe you can ref the edit photo in LinkedIn?

[ValentinH]

OK, for now, I'll add support for the rotation prop, this is easy. I'll see later if we should add mobile gesture to handle this within the component 🙂

[ValentinH]

Wow, I didn't see this LinkedIn feature, the cropper element looks exactly like this one! I will do a demo to show how to build this UI with react-easy-crop😎

[ValentinH]

Support added for rotation prop in v1.14.0: https://github.com/ricardo-ch/react-easy-crop/releases/tag/v1.14.0 🎉 I've updated the website demo: https://ricardo-ch.github.io/react-easy-crop/ 🙂 (I still have to add support for the rotation in the "Show results" popup).

[ayepRahman]

Woah that was fast. Great job Valentin!

On Fri, Jul 12, 2019 at 2:33 PM Valentin Hervieu notifications@github.com wrote:

Support added for rotation prop in v1.14.0: https://github.com/ricardo-ch/react-easy-crop/releases/tag/v1.14.0 🎉 I've updated the website demo: https://ricardo-ch.github.io/react-easy-crop/ 🙂

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/ricardo-ch/react-easy-crop/issues/47?email_source=notifications&email_token=AGJJD5HLKN6R5MPGSI7SEHTP7AQVPA5CNFSM4H7L6YM2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODZY2RMQ#issuecomment-510765234, or mute the thread https://github.com/notifications/unsubscribe-auth/AGJJD5EMU7QVHKQEQ3ELA2TP7AQVPANCNFSM4H7L6YMQ .

[ValentinH]

@ayepRahman supporting the rotation in the "Show results" popup is more tricky than expected. For now, I've removed it from the demo and marked the rotation as "experimental" in the ReadMe. Did you actually managed to use this new rotation prop? If yes, do you then generate the output image within the browser (canvas)?

[rafaelsorto]

This is amazing, I was about to fork the repo and see if I could get something like rotation rolling. I'll test the one that you added and come back with comments. Thank you for adding something like this. It's quite expected nowadays to just do pinch and zoom/rotate on mobile.

[ValentinH]

For now, we don't support rotating the image with gestures. I'd like to first ensure that the way rotation is handled now is correct:

• is the data exported by the lib enough to actually crop/rotate the original image? The croppedAreaPixels data might be wrong when rotation is different than 0.
• the "show output" demo should handled the rotation.
• what about edges detection? Right now, it's acting like the rotation is 0 which might not be the right approach.

Any help is welcome here because as I don't use the rotation myself, I might not be the right person to define those requirements.

Once all the points above are addressed, it should not be a big deal to support the gesture.

[MattyBalaam]

I’ve been having a little play with the rotation, but I’m hitting a wall trying to convert the co-ordinates to something that canvas will translate accurately.

If the crop is dead-center then using this kind of technique appears to work fine:

     context.translate(
        croppedAreaPixels.width / 2,
        croppedAreaPixels.height / 2,
      );

      context.rotate(getRadianAngle(rotation));

      context.translate(
        -croppedAreaPixels.width / 2,
        -croppedAreaPixels.height / 2,
      );

    context.drawImage(
      image,
      croppedAreaPixels.x,
      croppedAreaPixels.y,
      image.width,
      image.height,
      0,
      0,
      image.width, 
      image.height,
    );

However once the image is moved away from a central position then the image is moved in the wrong position and I just don’t have the knowledge about how to translating these x/y values.

[ValentinH]

@MattyBalaam Indeed, I faced the same issue. Everything goes wrong once the image is moved from the center. Also the edge detection is broken.

[MattyBalaam]

I’ll invest some time next week investigating this a bit further.

[MattyBalaam]

Thinking out loud... I wonder if a way to do it might be for having a canvas the size of the original image, the context to the rotated, then the image applied without cropping. The initial context should then be restored and then the result of this can then be cropped.

[ValentinH]

When do you translate the image if needed?

[MattyBalaam]

So after the rotation is applied the image is drawn with scaling, but not cropped. The cropping would be done afterwards. I'm thinking out loud without a laptop so this might not work how I imagine. But my thinking is that doing it this way will simulate more what is happening in the css transformation.

[MattyBalaam]

There is no doubt a more mathematical algorithm approach to doing this of course.

[ValentinH]

This is my main issue, I'm too lazy to do proper maths. Most of this library mathematical computations have been implemented by bruteforcing some formulas! 😃

[mbalaam]

So, I can confirm that this approach creates a crop that matches the preview. However at the moment as you mention the problem is that the edge detection is broken.

I’ll for the code sandbox with some working code later today.

[ValentinH]

This is awesome, it would be really nice to have a working example with the image export when rotation! We can deal with the edge detection later.

[mbalaam]

Here is a forked demo with rotation preview: https://codesandbox.io/s/react-easy-crop-demo-with-cropped-output-mlwif?fontsize=14

[ValentinH]

MAN!

This is so cool! Would you like to make a PR on the demo website to showcase this? Basically, this block should be uncommented, and you rotateImage() should be added.

Just one question, do you think there is a way to do the rotation and the crop/translate on the same canvas so that we only generate one image?

[mbalaam]

I’ve had a rethink, and here is an improved v2: https://codesandbox.io/s/react-easy-crop-demo-with-cropped-output-pd4v5

[ValentinH]

The code looks great! However, something might have been wrong because the output modal doesn't open anymore.

[mbalaam]

In the PR? I should have run it, I’ll check

[ValentinH]

No I meant in the sandbox

[mbalaam]

It’s working here. I’ve resaved it just in case.

[ValentinH]

Yes nevermind, it was due to my browser (Brave) tracking prevention.

[ValentinH]

Thanks to @mbalaam, the demo now supports the rotation props! 🎉

This mean that the only last remaining thing in the initial todo list is the edge detection. I think we can already remove the "experimental" flag from the readme as this is not that bad.

[ValentinH]

I'm closing this issue now. I have opened #52 for the edge detection.

[marvwhere]

Question: The "Show Image" is still not showing the right position, if you rotate and leave the center, right?

Or let it phrase the other way around: The croppedAreaPixels are totally off? Because when a landscape image and then it fits in the total width, x should always be 0 ?

I tested with the above v2 codesandbox

Is there any solution for it?

[ValentinH]

Indeed, the sandbox was not updated, only the demo on the website: https://ricardo-ch.github.io/react-easy-crop/ (source: https://github.com/ricardo-ch/react-easy-crop/tree/master/docs/src/components/Demo) I need to add another sandbox that uses the right code. 🙂

[marvwhere]

The Demo is giving out the wrong cutout too.

Reproduce: Rotate image by 270deg, move crop to total bottom. Click Show Result (Chrome OSX)

[mbalaam]

OK, seems to be wrong in certain cases… Could this be perhaps down to the changes I made with resizing the crop area?

@marvwhere can you confirm that at angles like 45 degrees the crop is correct?

[ValentinH]

Hmm this is weird, I was convinced that we had all the cases covered in the demo but this is clearly not case. It seems to be wrong when the image is translated to an edge with any rotation.

See:

@mbalaam do you think the demo was not updated to your latest example? I thought this was working in your example.

[mbalaam]

I could be that a change I made for 1.15.0 has broken the preview?

I’ll take another look over the next day or so.

[ValentinH]

Yes it might be. Maybe the way the output croppedArea has changed 🤔

I'm also coming back from holiday over this weekend, so I'll also investigate if needed.

[ValentinH]

I've found and fixed the issue locally. I'm adding some tests and publishing a fix soon 🎉

[MattyBalaam]

That's awesome news. Been really busy over the last couple of weeks and unable to find the time to investigate.

[ValentinH]

If you want to have a look: #63

[ValentinH]

A fix has been published under 1.16.1. I've also updated the demo website and this sandbox: https://codesandbox.io/s/q8q1mnr01w.

[mbalaam]

I’ve found some time to look at this as the demo was still showing the issue.

Good news is I think I know how to fix the canvas code and will open a PR. The clipping is happening because even though I am rotating on a canvas twice the size of the original image, once the crop is rotated around 90 degrees and then moved to an extreme edge the image is still clipped.

[ValentinH]

Indeed, in some really edge cases, a small part of the image can be clipped. 🙂

[mbalaam]

OK, I’m now generating the 'safe area' for the rotation based around the maximum width or height, so as far as I can tell the clipping issue is fixed now. Does anyone fancy giving it a battle test?

https://o87hi.csb.app/

[ValentinH]

I only see a black output when clicking the "Show results" button 😄

[mbalaam]

Hmmm, code sandbox doesn’t seem to have the right version saved going back to it… I’m going to need to work it out again